Atop many of the buildings in uptown Charlotte, you usually won’t notice the equipment that is hard at work keeping you cool in the summer. Marley Cooling Towers are often hidden from site and are often too quiet to even hear. As is the case in one building, the towers are so quiet that when they were factory tested for sound levels, the test could not be completed due to crickets chirping in the background. Cooling Towers can be operated quietly in many ways. From standard low sound fans and wide chord ultra quiet fans, too specially designed sound attenuation packages. But most importantly you need to know what sound levels your project needs. Then you need to specify equipment who’s sound data is certified. The proper specification verbiage is:
The cooling tower shall be designed for quiet operation, and shall produce an overall level of sound not higher than _______ dB(A) measured at _______ ft from the location: ______________________. Sound levels shall be independently verified by a CTI-licensed sound test agency to ensure validity and reliability of the manufacturers published values. Measurement and analysis of the sound levels shall be conducted by a certified Professional Engineer in Acoustical Engineering. Sound pressure levels shall be measured and recorded in the acoustic near-field and far-field locations using ANSI S1.4 Type 1 precision instrumentation and in full conformance with CTI ATC-128 test code published by the Cooling Technology Institute (CTI). All low sound options shall be CTI certified for thermal performance.
You can also include a table of sound data for the entire octave range and any distance beside or above the tower. Contact your cooling tower representative for assistance. And require the certification. Otherwise, you may not get exactly what you are expecting.
To learn more about available sound solutions, visit the SPX Website for the NC Class Crossflow Cooling Tower at http://spxcooling.com/products/marley-nc or the MD Series Counterflow Cooling Tower at http://spxcooling.com/products/marley-md.